2000 s type v8 cool air not cold heater works ok when turned

Customer Question

2000 s type v8 cool air not cold heater works ok when turned up. new compressor new drier pressure not where they should beand the low side needle is bouncing. so the repairer put in a new expansion valve and evaporator core and they were unable to verify that the air conditioning was delivering anywhere close to the goal temperature. they recommend jaguar dealer. dealer say heater control water valve. repairer wasn't so sure.